This disclosure relates to a method of identifying or producing an aptamer capable of binding to at least two target analyte variants, the method comprises generating a mixture of systematic evolution of ligands by exponential enrichment (SELEX)-selected aptamers by at least one-round of SELEX with a SELEX-compatible aptamer pool against the at least two target analyte variants in parallel or sequentially, sequencing the mixture of SELEX-selected aptamers that form complexes with each of the at least two target analyte variants by high-throughput sequencing, aligning the mixture of SELEX-selected aptamers that form complexes with each of the at least two target analyte variants by sequence alignment analysis, and identifying or producing the aptamer capable of binding to the at least two target analyte variants. Aptamers thereof and uses of the aptamers thereof are also disclosed.